The CAVC is a Court of Judicial Review, which means it is not like the VA Regional Office or the Board of Veterans’ Appeals (BVA). Its only job is to determine whether or not the BVA applied the law correctly when it denied your appeal. The CAVC does not accept new evidence or arguments of fact: it only accepts arguments founded in the law. When you proceed on your own (without representation) at the CAVC, you go up against experienced attorneys employed by the VA who know the law. Without a qualified attorney to identify the legal issues and arguments in your case, you are at a significant disadvantage.
The CAVC does not grant benefits. If your attorney is able to convince the VA’s attorney and the CAVC that the BVA did not apply the law correctly when it denied your appeal, the CAVC will remand (send back) your appeal to the BVA for a new decision. This is how you win at the CAVC.